Troy, N.Y. — The Hirsch Observatory at Rensselaer Polytechnic Institute will be open to the public every clear Friday evening throughout September and October.

The observatory, which is located atop the Jonsson-Rowland Science Center, will open at sunset and remain open for approximately three hours, weather permitting.

Members of the physics department and the Rensselaer Astrophysical Society will be on hand to talk about the night sky and answer questions.

Views of Uranus, Neptune, and Mars will be possible on clear autumn evenings, says graduate student Nicolle Zellner, who coordinates the project. The Ring Nebula, which is 1,500 light years away, will also be visible, Zellner says. This planetary nebula contains the corpse of a star (called a “white dwarf”) that blew away its atmosphere — a fate that awaits our sun in 5 billion years.

Friday, Nov. 2 and Saturday, Nov. 3, public viewing will take place from 7-9 p.m. The fall brings the Orion and Pleiades constellations back into view.

Saturday, Nov. 3, solar observing will take place from 12 p.m. to 3 p.m. Several telescopes will be set up so that people can safely view the sun. Sunspots and solar prominences will be visible.

The Hirsch Observatory will be closed in rainy weather or if two-thirds of the sky is obscured by clouds.

For information, call the Rensselaer physics department at 276-6310.